Low water-sensitive hydraulic fluids containing borate esters

ABSTRACT

A low water-sensitive hydraulic fluid composition which contains from about 20 to about 96 percent by weight of at least one borate ester as the base fluid. Such low-water sensitive hydraulic fluids are high boiling compositions particularly useful as brake fluids.

United States Patent 1 Sawyer et al. [4 1 Jan. 16, 1973' [54] LOWWATER-SENSITIVE HYDRAULIC [56] References Cited FLUIDS CONTAINING BORATEESTERS UNITED STATES PATENTS 5 Inventors: Arthur w Sawyer, Hamden; David3,625,899 l2/l97l Sawyer et al. ..252/75 A. Csejka, Orange, both ofConn. Primary Examiner-Leon D. Rosdol [73] Ass'gnee' Comm-anon AssistantExaminer-D. Silverstein [22] Filed: April 12, 1971 Attorney-EugeneZagarella, Jr., Gordon D. Byrl cit, [211 pp 133,452 35151:? F. Clements,F. A. lskander and Thomas- P.

Related US. Application Data [57] ABSTRACT [63] Continuation-m-part ofSer. No. 717,996, April 1,

1968, Pat. No. 3,625,899, which isacontinuation-in- A lowwater-sensitive hydraulic fluid composition P of y 1967, abandonedwhichcontains from about 20 to about 96 percent by weight of at least oneborate ester as the base fluid. [52] US. Cl ..252/78, 252/49. 6 s |owwater Sensitive hydraulic fluids are high 1 [51] Int. Cl. ..C09k 3/00,ClOm 3/48 ing compositions particularly useful as brake fluids [58]Field of Search ..252/74, 75, 77, 78, 49.6

25 Claims, No Drawings LOW WATER-SENSITIVE HYDRAULIC FLUIDS CONTAININGBORATE ESTERS This application is a continuation-in-part of co-pendingapplication Ser. No. 717,996 filed Apr. 1, 1968 and now U.S. Pat. No.3,625,899, which in turn was a continuation-in-part of application Ser.No. 653,338 filed July 14, 1967 and now abandoned.

This invention relates to new and improved, low water-sensitivehydraulic pressure transmission fluids for use in fluid pressureoperating devices such as hydraulic brake systems, hydraulic steeringmechanisms, hydraulic transmissions, hydraulic jacks, hydraulic lifts,etc. More particularly, this invention relates to hydraulic fluidshaving a low sensitivity to water which employ as the base fluid one ormore borate esters of glycol monoethers. The term base fluid as usedthroughout the specification and claims means the major activeingredient (not necessarily present in the major or largest proportion)of the hydraulic fluid, i.e. that ingredient which is most active inmaintaining the desired properties of the hydraulic fluid especially inthe face of aqueous contamination.

A great number of hydraulic fluid compositions have been suggested inthe art. Commonly, the hydraulic pressure transmission fluids, such asbrake fluids are made up of three principal units. The first is a baseor lubricant for the system which may include heavy bodied fluids suchas polyglycols, castor oil, mixtures of these materials, etc. Diluents,which are employed for the purpose of controlling the viscosity of thefluid as represented by glycol ethers, glycols, alcohols, etc., form thesecond basic unit. Finally, the third basic unit is represented by anadditive or inhibitor package comprising small quantities of materialswhich are added to control or modify various chemical and physicalproperties of the fluid, e.g. to reduce oxidation, to improve wettingand flow and to maintain the pH of the hydraulic system above 7 in orderto minimize corrosion. By varying the composition, particularly desiredproperties can generally be attained. However, hydraulic fluids havebeen subject to increasingly stringent requirements with regard to manyproperties, e.g. boiling point, viscosity, corrosiveness, lubricity,pour point and rubber swell. This has made it extremely difficult to Iproduce a desirable fluid since very often a change in composition whichimproves one or more of these or other essential properties willdetrimentally effect some other property. This problem is magnified whenwater gets into the hydraulic fluid since many of the properties areeffected, some to a substantial extent.

Hydraulic fluids, as exemplified by the commercial motor vehicle brakefluids, are hydroscopic by nature and therefore, absorb moisture fromambient atmospheres with resulting degradation of their boiling point.This effect that water has on the boiling point of hydraulic fluids hasbeen studied extensively and a great deal of public interest has beengenerated concerning the safety qualities of hydraulic fluids especiallybrake fluids as is pointed out, for example by C. F. Pickett in anarticle entitled Automotive Hydraulic Brake Fluids published as part ofthe 51st Mid-Year Meeting Proceedings of the Chemical SpecialtiesManufacturing Association, Inc., NY. (1965). As indicated in theabove-noted article, when a small amount of water, e.g. 3.5 percent byweight was added to various commercial brakefluids, some'having initialavailable commercial fluids is more readily understood when thefollowing facts are considered. First of all, it is known that hydraulicbrake fluid temperatures can reach rather high levels and often approachand even exceed the 300F. level. This is substantiated by the results offield studies in 1966 by the Society of Automotive Engineers (SeeSP-338, Automotive Brake Evaluation Under Customer Usage Conditions,pp.l and 2, 1968) wherein it was shown that brake fluid temperaturesapproached 270F. under typical driving conditions of vehicles which wereloaded only to their manufacturers recommended limit. it couldreasonably be assumed from these results, that when abnormal conditionsare encountered temperatures would exceed 270F. and approach and evenpass It is also known that so-called conventional type motor vehiclesoften accumulate small amounts of moisture in their hydraulic fluidsduring usage. This is substantiated by results disclosed in a meeting ofthe SAE Hydraulic Brake Systems Actuating Committee in 1966 (See minutesof meeting of October 26-27, 1966) and further by the report of CharlesB. Jordan, Effect of Water on Hydraulic Brake Fluid, U.S. Army Coatingand Chemical Laboratory, May, 1966. These articles clearly show thatamounts of water have been accumulated in hydraulic brake fluids underuse conditions in varying proportions and have often reached levels ofup to 3.5 percent and even have been as high as 5 percent by weight. Thefact that hydraulic fluids do accumulate some water during usage isfurther supported by the SAE Standard J-l703 which requires certainwater'tolerance tests to be passed after the addition of 3.5 percent byweight water and also, requires a corrosion test to be passed after theaddition of 5 percent by weight water to the brake fluid.

From the above discussion, it can readily be understood that hydraulicfluids can under certain conditions approach temperatures of themagnitude of 300F. and higher and furthermore such fluids can accumulatesmall amounts of moisture during usage. Thus, hydraulic fluids whichhave low dry boiling points and are sensitive to water to a large degreecan encounter problems such as vapor lock which can result in thefailure of a hydraulic brake system and consequently cause an accident.This clearly illustratesthe advantage of the hydraulic fluids of thisinvention which possess a high degree of water tolerance and are able tomaintain their boiling points at higher and safer levels.

The seriousness of the problem of water accumulation and its effects onthe hydraulic fluid system is further signified by the fact that theU.S. Department of Transportation presently is considering acceptance ofstandards for motor vehicle brake fluids which would for the first timeinclude a minimum wet reflux boiling point (equivalent to approximately3.5 percent by weight of water added). The proposed standards includeone for a fluid having a minimum dry reflux boiling point of 401F. and aminimum wet reflux boiling point of 284F. and another for a fluid havinga minimum dry reflux boiling point of 446F. and a minimum wet refluxboiling point of 320F. The term dry reflux boiling point as used hereinis defined as the boiling point of the hydraulic fluid as delivered tothe consumer or distributors (Le. fluid ready for use). Wet refluxboiling point is the boiling point of the hydraulic fluid after adiscrete amount of water has been added thereto.

The above considerations clearly point out the need for a hydraulicfluid which has a low sensitivity to water and can maintain certainproperties and characteristics when amounts of water commonlyencountered during use are present.

There are various hydraulic fluids known in the art as shown for examplein Introduction to Hydraulic Fluids by Roger E. Hatton, ReinholdPublishing Corp. (1962); U.S. Pat. No. 2,998,389 issued to Chester M.White on August 29, 1961 and U.S. Pat. No. 3,377,288 issued to Arthur W.Sawyer on Apr. 9, 1968. Generally, these fluids do not have the lowwater sensitivity that is required to maintain their original propertiesafter there is an accumulation of moisture.

One of the basic-objects of this invention is to prov vide hydraulicpressure .transmission fluids for use in hydraulic systems which retainto a high degree, their original properties when water is accumulated,i.e. they have a low sensitivity to water.

Another object of this invention is to provide hydraulic pressuretransmission fluids which are extremely high boiling compositions andwhich maintain relatively high boiling points even when water isaccumulated in the hydraulic fluid composition.

Another object of this invention is to provide a hydraulic pressuretransmission fluid having an initial dry reflux boiling point of atleast about 450F. and a wet reflux boiling point of at least about 320F.when about 3.5 percent by volume of water (equivalent to about 3 .4percent by weight) is present.

A further object of this invention is to provide a hydraulic pressuretransmission fluid having a high degree of lubricity while maintainingdesired viscosities within a predetermined range under a wide variationof temperature conditions.

These and other objects of this invention are accomplished .with thehydraulic fluids of this invention which generally comprise from aboutto about 96 percent by weight, based on the total hydraulic fluidweight, of at least one borate ester of a glycol monoether as the basefluid. Generally the remainder of the fluid is comprised of diluent andone or more additives.

The hydraulic fluids of this invention are especially desirable becausethey have a low water sensitivity and are particularly useful as brakefluids since they can retain to a high degree the original properties ofthe fluid after water is accumulated. Additionally, the hydraulic fluidsof this invention are of low cost, possess a high boiling point, areessentially odorless and colorless, possess a high degree ofcompatibility with other fluids and exhibit a very low rate ofcorrosivity.

Another feature of this invention is the highly satisfactory rubbercompatibility of the novel fluids as shown in tests carried outaccording to SAE Standard Jc (see Table l). Fluids previously employedhave utilized more expensive materials such as 2-ethylhexanol,heptanols, butyl ethers of glycols, or diethers of glycols in an amountfrom about 10 to about 30 percent by weight of the total composition toachieve the desiredrubber swelling characteristics whereas the hydraulicfluids of this invention provide satisfactory rubber swelling propertieswithout the addition of a component for this purpose. The importance ofthe rubber swelling properties of the fluid cannot be overlooked sincetoo little swelling will result in leakage of the fluid passed therubber cup sealing means and passed the piston in hydraulic cylinderswith corresponding loss of power. On the other hand fluids which causetoo much rubber swelling are not desirable in that they destroy thestructural properties of the rubber sealing cups in hydraulic cylinders,which in turn results in malfunction or inoperativeness of the unit.

The hydraulic fluids of this invention generally comprise threeprincipal units: (l) base fluid, (2) diluents and (3) additives. Thecomponents of these units and the proportions thereof are described indetail below.

BASE FLUID The base fluid employed in the novel hydraulic fluids of thisinvention generally comprises at least one borate ester of a glycolmonoether. More particularly, the hydraulic fluids of this inventionwill comprise from about 20 to about 96 percent by weight, based on thetotal hydraulic fluid weight, of at least one borate ester of a glycolmonoether. Preferably, the amount of borate ester will vary from about30 to about 92 percent and more preferably from about 54.5 to about 92percent by weight, based on the total hydraulic fluid weight. When usinghydraulic fluids which can safely operate under somewhat lowertemperature conditions, the range of borate ester used may vary fromabout 20 to about 55.4 percent and preferably from about 30 to about54.4 percent by weight, based on the total weight of the hydraulicfluid. Generally, when 54.5 percent borate ester is used, the hydraulicfluid can maintain a wet boiling point (-35 percent by volume wateradded equivalent to about 3.4 percent by weight) of at least about 350F.When 20 and'30 percent borate ester is used, a wet boiling point of atleast about 320F. and 330F. respectively can vbe maintained.

Although a wide variety of borate esters can be employed as the basefluid in the novel hydraulic fluids of this invention, an especiallyuseful class of borate esters are the so-called tri borate esters ofglycol monoethers having the general formula l l( a)u ]3 l wherein R, isa lower alkyl radical containing from one to four carbon atoms,preferably one to two, R, is al kylene of from two to four carbon atoms,preferably two to three, and y is an integer from two to four inclusive.The R and R, groups may be either straight or branched chain structures.Borates of the above-mentioned type include, for example: [CH (OCH CH O]mixture is maintained between about 0C. and about 3 190C. and desirablyat the distillation temperature of the water-solvent azeotrope. Afteressentially complete removal of the water formed during esterification,the excess solvent is conveniently removed from the reaction mixture bydistillation. The borate ester product, which is left in a residue, maythen be recovered by distilling under reduced pressure or by extractionwith a suitable solvent followed by evaporation of the solvent. Forexample, the compound [C H (OCH CH O] --B can be prepared by reactingtwo moles of C l-1 (OCHCH Ol-l, 0.67 mole of orthoboric acid and 700 ml.of ethylbenzene with heating and mixing to yield 198 grams of the ester,a water-white liquid boiling at 222223 C. (5 mm. Hg). It is noted thatin the preparation of these esters, a small proportion of concomitantreaction products may be formed and other minor impurities may also bepresent. Generally, the predominant portion of such other reactionproducts formed is a boroxine type compound having the following generalstructure:

wherein R, is derived from the particular glycol ether being used, e.g.CH;,(OCH CH O-, C H (OCH cH O, etc. The amount of such concomitantreaction products formed and other impurities present may be up to about10 percent by weight if the reacted mixture is not distilled.Distillation will reduce the amount of other reaction products andimpurities to about 1 percent or less, however, either the distilled orundistilled product can be used provided the reaction medium or solventis stripped off. The term borate ester as used in the specification andclaims is intended to include relatively pure borate ester as well ascrude borate ester which contains impurities and other by-productsformed during preparation as described above. The preparation of thetri-borate esters per se is more completely described in US. Pat. No.3,080,412 issued to D. M. Young on Mar. 5, 1963. It is of interest tonote that this patent (US. Pat. No. 3,080,412) discloses the use oftri-borate esters, such as tris [2-(2- ethoxyethoxy)ethyl] borate, asstabilizers and corrosion inhibitors for lubricants and non-aqueoushydraulic fluids. However, use of these esters for such purposes, i.e.as a stabilizer or corrosion inhibitor, would not impart satisfactorylow water sensitivity to the hydraulic fluid since such usage wouldgenerally be in very small or minor proportions (eg from 0.5 to 2percent) in accordance with the generally accepted practice in the art(e.g. see US. Pat. No. 3,403,104 issued to P. B. Sullivan on Sept. 24,1968).

A second highly useful class of borate esters includes compounds of thegeneral formula: [R (OCH CHR (OCH2CH 3)nO]3 B (ll) wherein R and R areindependently selected from the group consisting of hydrogen and methyl,m and n are positive integers whose sum is from 2 to 20 and R is alkylof from one to four carbon atoms and with proviso that one of R and R ismethyl and one of R and R is hydrogen. R may be straight chain orbranched alkyl. Borate esters of Type ll can be prepared in the generalway as those esters previously described (Type 1) above, utilizing theso-called block type glycol monoethers. The preparation of esters ofType ll is described in detail in US. Pat. No. 3,316,287 issued to L. G.Nunn, Jr. et al. on Apr. 25, 1967. Type II borate esters useful inpreparing the novel fluids of this invention include, for example:

Another class of borate esters useful in the fluid compositions of thisinvention include esters having heteric oxyalkylene chains, that is,oxyalkylene chains in which oxyethylene and oxypropylene units aredistributed randomly throughout the chain. These Type III esters havethe general formula:

1[ gl )a (m) Rg represents a heteric oxyalkylene chain having theformula:

[ Z UT z QS where the sum of r and s is not more than 20 and wherein theweight percent of oxyethylene units in the said chain is not less than20 based on the total weight of all the oxyalkylene units in the chainand R, is alkyl of from one to four carbon atoms and may be straight orbranched chain. The preparation of Type 111 esters can be accomplishedin the same general manner as the preparationof Types 1 and 11 describedabove by reacting orthoboric acid in the presence of toluene with aheteric glycol monoether of the formula:

R,[Rg]Ol-l where R, and Rg have the same meaning as previously setforth. Glycol monoethers of this class can be conveniently prepared bymethods well known in the art such as the process described in U.S. Pat.No. 2,425,845 issued to W. J. Toussaint et al. on Aug. 19, 1947.

A fourth type of borate esters suitable for use in the fluidcompositions of this invention have the general formula:

preferably one to two, R' is hydrogen or alkyl of from one to fourcarbon atoms, preferably one to two, R" is alkylene of two to fourcarbon atoms, preferably two to three, and y is two to four. The R, Rand R groups may be straight chained Qrbranched. It is also intendedthat the alkylene oxide group (O-R") in the above formula (V) includemixtures of said alkylene oxides.

Illustrative of the diluents of this type (V) are the followingcompounds: diethylene glycol monomethyl ether, diethylene glycolmonoethyl ether, diethylene glycol monoisopropyl ether, diethyleneglycol monoisobutyl ether, triethylene glycol monomethyl ether,triethylene glycol monoether ether, triethylene glycol mono-n'butylether, tetraethylene glycol monomethyl ether, tetraethylene glycolmonoethyl ether, dipropylene glycol monomethyl ether,

wherein T T and T are each an independently selected alkyl group havingfrom one to four carbon atoms, R.,, R R R R and R are independentlyselected from the group consisting of hydrogen and methyl, n and m arepositive integers independently selected in each chain and whose sum ineach chain is from 2 to 20, and with the proviso that in no more thantwo of the chains is the sum of n and m the same. It is also noted thatT T and T may be a straight or branched chain alkyl group.

Borate esters of this type can be prepared in the same way as theprocess described for Type I esters previously mentioned.

Type IV borate esters suitable for use in the fluids of this inventioninclude, for example:

dipropylene glycol monoethyl ether, tripropylene glycol monomethylether, tripropylene glycol monoethyl ether, tripropylene glycolmono-n-butyl ether, tetrapropylene glycol monomethyl ether,

It gramme ted Embers esters or T es I], lit and IV may includeconcomitant reaction products and other impurities of the type asdescribed above for Type I esters. Reference to these types of borateesters in the specification and claims is intended to include relativelypure borate ester as well as crude borate ester which containsimpurities and other by-products formed during preparation as describedabove for Type I.

DILUENTS This diluent portion of the hydraulic fluid composition of thisinvention generally will comprise one or more compounds selected fromthe group consisting of (a) glycol monoethers or diethers (b) glycolsand polyglycols and (c) aliphatic saturated alcohols.

More particularly, the glycol monoethers or diethers have the formula:

l "l., 0 wherein R is alkyl of from one to four carbon atoms,

mula (V) may be used, the following glycol ethers are particularlyuseful: diethylene glycol monomethyl ether, diethylene glycol monoethylether, diethylene glycol monobutyl ether, triethylene glycol monomethylether, triethylene glycol monoethyl ether, triethylene glycol monobutylether, tetraethylene glycol monomethyl ether, tetraethylene glycolmonoethyl ether and tetraethylene glycol monobutyl ether.

The glycol ethers are the most preferred diluent since their use willresult in a fluid having a desirably high boiling point with goodviscosity and water solubility properties. Most preferred of the glycolethers are the ethylene glycols.

The second group of useful diluents are the glycols and polyglycols,including alkylene, polyalkylene and polyoxyalkylene glycols, having amolecular weight of from about 60 to about 450 and preferably from aboutto about 300. Illustrative of such type diluents are the followingcompound: ethylene glycol, propylene glycol, hexylene glycol, diethyleneglycol, dipropylene "@861, I triethylene glycol, tripropylene glycol,

polyethylene glycol and polypropylene glycol.

The use of the glycols and polyglycols as diluents is not as desirableas the glycol ethers since their use may result in some loss of fluidityat very low temperatures, however, they may be used in conditions wherethe requirements are not as demanding.

The third type of useful diluents are aliphatic, saturated, monohydricalcohols containing from six to 13 carbon atoms, preferably from eightto 10. Illustrative of such diluents arc the following alcohols:hexanol, octanol, isooctanol, decanol, isodecanol, dodecanol, andtridecanol.

Since the use of the aliphatic alcohols in a high boiling hydraulicfluid may result in some loss of water solubility, they are not asdesirable as the glycol ethers. However, they may be used in conditionswhere the requirements are not as stringent.

The diluent portion of the hydraulic fluids of this invention generallywill comprise from to about 80 percent by weight, preferably from about3 to about 70 and more preferably from about 3 to about 45 percent byweight, based on the total weight of the hydraulic fluid composition.

While the above diluents, especially the glycol ethers, are particularlypreferred, other diluents may be used if the desired properties andcharacteristics of the hydraulic fluid can be attained. For example,certain diesters derived from organic aliphatic acids and aliphaticalcohols might be usefully employed. Examples of diesters which might beused include dibutyl adipate, bis(methoxyethyl) azelate, diisopropylsuccinate, dipropylene glycol diproprionate and triethylene glycoldibutyrate.

ADDITIVES When desired, various additives may be added to the hydraulicfluids of this invention to control or modify various chemical andphysical properties of the fluids. Among the various types of additiveswhich can be added to the hydraulic fluids of this invention areincluded: inhibitors for pH and corrosion control, antioxidants, rustinhibitors, viscosity index improvers, pour point depressants, lubricityagents, antifoamants, stabilizers, demulsifiers dyes and odorsuppressants. Generally, the total amount of additives which may beincorporated into the fluid composition will vary depending on theparticular composition and the desire properties. More particularly, thetotal amount of additives .will comprise from 0 to about percent andpreferably from about 0.1 to about 8.0 percent by weight based on thetotal weight of the hydraulic fluid composition.

For example, inhibitors for pH and corrosion control, such as alkalineinhibitors as exemplified by the alkali metal borates, can be employedin an amount sufficient to maintain alkaline conditions in the fluidcompositions, e.g. a pH value of from about 7.0 to about 11.5. Theseinhibitors are generally added in an amount of from 0 to about 8.0percent by weight based on the total weight of the hydraulic fluidcomposition and preferably from about 0.2 to about 6.0 percent by weighton the same basis. Useful inhibitors include alkali metal borates, suchas sodium borate, potassium tetraborate, etc.; sodium meta arsenite;alkali metal salts of fatty acids, such as potassium oleate, thepotassium soap of rosin or tall oil; alkylene glycol condensates withalkali metal borates, such as the ethylene glycol condensate ofpotassium tetraborate; amines, for example, ethanolamine, methyldiethanolamine, diethanolamine, isopropanolamines( mono, di and tri),di(2-ethylhexyl) amine, di-N-butyl amine, monoamyl amine, diamylamine,dioctylamine, salicylal monoethanolamine, di-B-naphthyl-p-phenylenediamine, N,N '-disalicylidene LZ-pmpanediamine,

N,N-disalicylal ethylene diamine, dicyclohexylamine, and amine saltssuch as mono or dibutyl ammonium borate; phosphites, such as triphenylphosphite, tri(tertamylphenyl) phosphite, diisopropyl phosphite, etc.;mercaptobenzotriazole; morpholine compounds including alkyl morpholineshaving from one to four carbon atoms in the alkyl group such as N-ethylmorpholine, N-isopropyl morpholine, N-butyl morpholine; N-phenylmorpholine, N-(Z-aminoethyl) morpholine, N-(Z-hydroxyethyl) morpholine,etc.; phosphates, including the alkali metal phosphates, dibutyl aminephosphates, the dialkyl acid 0- phosphates and amine salts thereof;triazoles including benzotriazole, 1,2-naphthotriazole, 4-nitrobenzotriazole, tolutriazole, aminobenzotriazoles such asS-acylaminobenzotriazole, and alkyl triazoles having one to 10 carbonatoms in the alkyl group as exemplified by methyl triazole, ethyltriazole, n-propyl triazole, tertiary butyl triazole, hexyl triazole,isodecyl triazole, etc. Other useful corrosion inhibitors includeadenine, 4-methylimidazole, 3,5-dimethyl pyrazole, 6- nitroidazole,imidazole, benzimidazole, quaninie, in-

dazole, ammonium dinonylnaphthaline sulfonate, dioleyl thiodipropionate,ethylbenzoate, ethyl-paminobenzoate, cyclohexyl ammonium nitrite,

diisopropyl ammonium nitrite, butynediol, glycerin,l,3,5-trimethyl-2,4,6-tris (3,5-di-tert. butyl-4-hydroxybenzoyl),4,4'-methylene bis(2,6-di tert. butylphenol), 4-hydroxymethyl-2,6-di-tert. butylphenol, 4,4'-methylene bis (4methyl-6-tert.butylphenol), salicylal-o-aminophenol, 2,6-di-tert. butyl-2-dimethylamino-p-cresol, 4,4-thio bis-(6-tert. butyl-ocresol). Mixturesof the above-mentioned inhibitors can be employed if desired.

An antioxidant may be used as an additive in the hydraulic fluidcompositions of this invention if desired. Generally the amount ofantioxidant used will vary from 0 to about 2 percent and preferably willbe from about 0.001 to about 1.0 percent by weight'based on the totalweight of the fluid composition. Typical antioxidants include phenoliccompounds, such as 2,2-di- (i-hydroxyphenyl) propane, phenothiazine,phenothiazine carboxylic acid esters, N-alkyl or N arylphenothiazines,such as N-ethyl phenothiazine, N- phenyl phenothiazine, etc.;polymerized trimethyldihydroquinoline; amines, such asphenyl-alphanaphthylamine, phenyl-beta-naphthylamine, dioctyldiphenylamine, N,N-di-B-naphthyl-p-phenylene diamine, p-isopropoxydiphenylamine, N,N-dibutyl-pphenylene diamine, diphenyl-p-phenylenediamine, N,N-bis( l ,4-dimethylpentyl)-p-phenylene diamine,N,N'-diisopropyl-p-phenylene diamine, p-hydroxydiphenylamine, etc.;hindered phenols such as dibutyl cresol, 2,6-dimethyl-p-cresol,butylated 2,2-di-(4- hydroxyphenyl propane, n-butylated aminophenol,butylated hydroxyanisoles, such as 2,6dibutyl-p-hydroxyanisole;anthraquinone, dihydroxyanthraquinone, hydroquinone,2,5-di-tertiarybutylhydroquinone, 2-tertiary butylhydroquinone,quinoline, p-hydroxydiphenylamine, phenyl benzoate, 2,6-dimethylp-cresol, p-

hydroxyanisole, nordihydroquaiaretic acid, pyrocatechol, styrenatedphenol, polyalkyl polyphenols, sodium nitrite, etc. Mixtures of theabovementioned antioxidants can be employed, if desired it should beemphasized that with a variety of the fluids of this invention, whichare suitable for a wide range of industrial application, a separateantioxidant is not required.

The above-noted inhibitors and additives are merely exemplary and arenot intended as an exclusive listing of the many well-know materialswhich can be added to hydraulic fluid compositions to obtain variousdesired properties. Numerous additives useful in hydraulic fluids aredisclosed in Introduction to Hydraulic Fluids by Roger E. Hatton,Reinhold Publishing Corp., (1962).

Formulation of the novel fluid of this invention is accomplished byblending the components to a homogeneous stage in a mixing vessel. Thepreferable blending temperature is from about 50l25F. It is preferableto warm the solution during preparation to facilitate dissolution. Theblending of the compounds is conveniently conducted at atmosphericpressure in the absence of moisture.

In general, any suitable method can be used in preparing the liquidcompositions of this invention. The

components can be added together or one at a time, in"

any desired sequence. It is preferable, however, to add the glycol ethercomponent. All components are mixed until a single phase composition isobtained.

The following examples which illustrate various embodiments of thisinvention are to be considered not limitative.

EXAMPLE 1 A hydraulic fluid having the following composition wasprepared:

Percent by Weight [CH,(OCH,CH O] -B 67.39 Triethylene glycol monomethylether 23.20 Diethanolamine 1.78 Polyethylene glycol (Moi. wt. 300) 7.62Sodium Nitrite 0.01

Total 100.00

The fluid composition of this example was tested according to theprocedures set forth in Hydraulic Brake Fluid SAE Standard J70c forheavy duty types 70R] and 70R3 hydraulic brake fluid. Pertinent datarelating to these tests, which illustrates the outstanding properties ofthis novel fluid, is shown in Table l. The fluid of Example 1 was foundto satisfy completely the requirements for SAE heavy duty type 70R3hydraulic brake fluid. Table 2 illustrates the effect of added water onthe hydraulic fluid of Example l and compares it with the effect ofwater on a conventional or commercially the antioxidant and alkalineinhibitor as a solution in available fluid.

TABLE 1.-PROPERTIES OF WATER I NSE NSITIVE BRAKE FLUID ()F EXAMPLE 1(Tests conducted according to procedures set forth in Society ofAutomotive Engineers Standard .1700) Test results water insensitive SAER3 fluid of Test specification Example 1 Boiling point (min. 374 F 407F. Flash point (min.) 179.6 F 330 F. Viscosity:

40 F. (max.) 1,800 cs 1,790 es. 122 F. (m n.).. 4.2 cs 7.34 cs. 212 F.(mm.) 1.5 cs 2.71 cs. pH 71l.5 7.70. Stability at high temperature:

Boiling point (min) 495 F. Boiling point change (max.) 2 F. Corrosiontest (wt. change mgJsq. cm

te Tinned iron Sedimentation, percent by vol. (max.)

Gelling fluid/water mixture on Crystalline deposit jar walls or strips.0. pH fluid/water mixture 7.50. Rubber cups:

Swelling (max.) Softening (max.) Fluidity and appeeranc (1 test) 40 F.six days: Black contrast lines, HP chart Stratification-scdimentatlon.Air bubble travel time (max.) 10 sec Z sic 68 l six hours:

Black contrast lines, HP chart Clearly discernible" Clear.StratificaMon-sedimentation. None None. Air bubble travel time (max.) 86see 5 see.

Patent No. 4,114,514 li-Fol. N0. 070

' Evaporation test:

Percent loss (max.) percent 60 percent. Gritty or abrasive reside. N oneNone. Pour point (max.) 23 F 23 F. Water tolerance:

40 F., 24 hours:

Black contrast lines, HP chart (Jlcarly discernible. Clear.Stratification-sedimentation.. None..." None. Air bubble travel time(max.) 10 sec 3 sec. F., 24 hours:

Stratification None......... None. Sedimentation, percent by vol.(max.). 0.05 percent... 0.0l percent.

n a. M- Iablc l.. Continued Test results water insensitive SAE 70R3fluid of Test specification Example 1 Compatibility: 7 WE, ,7 V N 40 F.,24 hours:

Black contrast lines, HP chart. Clearly dlsccrniblo Clear.Stratiiication-sedimentation. None Nono. 140 F., 24 hours:

Stratification None Do. Sedimentation, percent by vol. (max) 0.05percent 0.01 percent. Resistance to oxidation (peroxide test):

Fitting of metal strips:

Aluminum None None. Cast iron .do Do. Weight loss in mg./sq. cin.:

Aluminum alloy (max.) 0.05 0.00. Cast iron (main) 0.30 +0.01. Effect onrubber -158 F.:

Hardness decrease:

Natural (max.) 10 2. SBR (man).-.- 10 3. Base diameter increase: 7

Natural 0.006"0.055 0.013. SBR- 0.006"-0.056 0.019.

Pat. No. 4, 114, 514 671 Disintegration rubber cups None None.

Effect on SBR rubber --248 F.:

Hardness decrease (max.) 4. Base diameter increase 0.006"-0.055 0.033.Disintegration rubber cups-.- None None.

Color Straw.

Simulated Service Performance Procedure No. 2 (85,000 strokes; 248F./1,000 p.s.i.)

Corrosion of metal parts as evidenced by discernible pitting None None.Change in initial diameter of any cylinder or piston (max.) 0.005 Do.Lip diameter interference set of rubber cups:

Wheel cylinder cups (max.) 65 percent ,7.2 percent. Master cylindercups:

Primary (max.) do 15.4 percent. Secondary (ma-x.) .do 0.0 percent.Hardness decrease of rubber cups:

Wheel cylinder cups (max.) 15 4. Master cylinder cups:

Primary (max.) 15 6. Secondary (rnax.) 15 5. Operating condition ofrubber cups as evidence by excessive tackiness, scoring, scuifing,blistering, cracking, Satisfactory Satisfactory.

chipping, or change in shape.

Fluid loss during any 24,000 stroke period (max.)

Freezing or malfunction of cylinder pistons Gum deposited on metal partsof cylinder walls that a e or cannot be removed with ethanol. Do.

Deposits formed or adhering to cylinder walls that are abrasive orcannot be removed with ethanoL. Do.

Fluid loss during 100 strokes at end of test (max.) 36 m1 coondition offluid and brake cylinders by evidence of sludg elling or grlttinesslikely to cause improper None None.

ra e act on.

Percent sediment in fluid drained from wheel cylinders 72 hoursequilibrium (max.) 1.5 percent 0.05 percent.

Percent sediment in fluid drained from master cylinder 72 hoursequilibrium (max.) d Do.

Decrease in base diam. of rubber cups:

Wheel cylinder cups (max.) 0.020 percent, Master cylinder cups:

Primary (man) 0.025 percent. Secondary (max.) 0.035 percent.

TABLE 2.EFFECT OF ADDED WATER 0N BOILING POINT EXAMPLE 2 OF HYDRAULICFLUID OF EXAMPLE 1 Percent by 1: Retlu boiling point, 11 weight LOWwater :i( z 2)3 ]3 Cogveni seisitiivt Triethylene glycol monomethylether 6.68 u 0 Polyethylene glycol (Mol. wt. 300) 1.83

water fluid A Example 1 Methyldiethanolamine 1.99

0.0 ercent b vol. (dry) 484 497 sod'um Nm'lte 1.0. 380 450 5 Total100.00

3.38 294 are 5 V V k *3.5 ml. H O/IOO ml. fluid. The reflux boilingpoint (dry) of the above fluid was measured and found to be 552F. atatmospheric presf 1 icomposltlon of Conventlonal Flmd A was as sure. Totest the low water sensitivity of the fluid com- 0 o weight position ofExample 2 a composition consisting of I00 percent A 50-50 weight percentethylene oxide-propylene oxide random parts by volume of the flu ld plus35 parts by volume of 31% 3230 ea p od with butyl alcohol cwt. 20 0water was prepared and it was found to have a reflux latens nab}man giin'gitajj"31331332313313:1:33;: 1g boiling point (wet) at atmosphericpressure of 402F.

riethylenegyco monoe y at er Triethylene glycol monobutyl ether 10.0 g pthat the fluid has an exceptional} low water Ethylene glycolsensitivity. For example, when a conventional brake Dlphenylolpropane... -1 n h b o Condensate oi7 moles of hylenc glycol with 1 moleof potns- 0 2 U1 W 16 0115 above 550 F. 18 tested in the same slum L;manner, the reflux boiling point drop is about 250F or Total 100.0 moreThe fluid composition of this example was also tested according to theprocedures of SAE Standard J70c for water tolerance and evaporation andwas found to pass both of these tests. 1 All reflux boiling pointmeasurements in this example and in the other examples of thisspecification were conducted in accordance with the procedure of SAEStandard 1700.

EXAMPLE 3 Percent by Weight [CH,(OCH,CH,) O],- B 66.0 Triethylene glycolmonomethyl ether 21.9 N-ethyl morpholine 4.4 Polyethylene glycol (M01.wt. 300) 7.7 Total 100.0

The reflux boiling point (dry) of this fluid was measured and found tobe 440F. at atmospheric pressure. On addition of 3.5 parts by volume ofwater to 100 parts by volume of the fluid there was obtained a fluidhaving a reflux boiling point (wet) at atmospheric pressure of 353F.When tested according to theprocedure of SAE Standard .l70c, this fluidpassed the evaporation requirement for SAEheavy duty type 7OR3 brakefluid.

EXAMPLE 4 Percent by Weight l a(OCH: 1)a0]:-B 67.04 Triethylene glycolmonomethyl ether 21.72 N-phenyl morpholine 1.89 Diethanolamine 0.85Polyethylene glycol (M01. wt. 300) 8.50

Total 100.00

Properties:

Reflux boiling point (dry) at atmospheric pressure Reflux boiling pointwet) at atmospheric pressure of 3.5 parts by volume of water and 100parts by volume of fluid of Example 4 367F.

Reflux boiling point (wet) at atmospheric pressure of 3.5 parts byvolume of water and 100 parts by volume of fluid of Example 5 372F.

Viscosity 40F. 1620 cs.

212F. 2.74 cs.

Water Tolerance Test Passed water tolerance test at -40F. and 140F. ac-

cording to procedure of SAE J70c.

EXAMPLE 6 Percent by 7 Weight [C,H,(OCH,CH,) O],-B 82.78 Triethyleneglycol monoethyl ether 10.00 Methyldiethanolamine 2.20 Polyethyleneglycol (Mol. wt. 300) 5.00 Sodium. nitrite 0.02 Total 100.00

16 Properties:

Reflux boiling point (dry) at atmospheric pressure Reflux boiling point(wet) at atmospheric pressure of 3.5 parts by volume of water and 100parts by volume of fluid of Example 6 383F.

Viscosity 40F. 1910 cs.

212F. 2.82 cs. Water Tolerance Test Passed 40F. and 140F. watertolerance test according to procedure of SAE J c.

EXAMPLE 7 Percent by Weight [CH,(OCH,CH,),O],-B 70.13 Triethylene glycolmonomethyl ether 20.00 Diethanolamine 1.86 Triethylene glycol (Mol. wt.150) 8.00 Sodium nitrite 0.01 Total 100.00

Properties:

Reflux boiling point (dry) at atmospheric pressure Reflux boiling point(wet) atmospheric pressure of 3.5 parts by volume of water and parts byvolume of fluid of Example 7 381F.

Viscosity 40F. 2050 cs. 212F. 2.80 cs. Corrosion Test Passed corrosiontest according to procedure of SAE J70c.

Water Tolerance Test Passed water tolerance test at 40F. and F. ac-

cording to procedure of SAE J70c.

EXAM PLE 8 Percent by Weight [C H (OCH,CH,),0];,-B 28.29 [CH;,(OCH,CH,).,O],-B 55.58 Triethylene glycol monomethyl ether 8.05 Polyethyleneglycol (Mol. wt. 300) 6.1 l Methyldiethanolamine I 1.94 Sodium nitrite0.03

Total 100.00

Properties:

Reflux boiling point (dry) at, atmospheric pressure Reflux boiling point(wet) at atmospheric pressure of 3.5 parts by volume of water and 100parts by volume of fluid of Example 8 400F.

Viscosity 40F. 2540 cs.

212F. 3.27 cs. Water Tolerance Test Passed water tolerance test at -40F.and 140F. ac-

cording to procedure of SAE .l7Oc.

EXAM PLE 9 Percent by Weight Boratc Ester D (Described below) 8046Triethylene glycol monobutyl ether 1 1.40 Diethanolamine 2.04Polyethylene glycol (M01. wt. 300) 6.08 Sodium nitrite 0.02 Total 100.00

Properties:

Reflux boiling point (dry) at atmospheric pressure Reflux boiling point(wet) at atmospheric pressure of 3.5 parts by volume of water and 100parts by volume of fluid of Example 9 385F.

Viscosity 40F. 1470 cs.

212F. 2.64 cs. Water Tolerance Test Passed water tolerance test at 40F.and 140F. according to procedure of SAE J70c.

Borate Ester D employed in the above fluid, which is an example of aType IV ester, was prepared in the following manner: One mole (61.8grams) of orthoboric acid was added to a solution of one mole- (164grams) of triethylene glycol monomethyl ether and 50 ml. of toluene. Themixture was heated to the boiling point and one mole (18 ml.) of waterwas removed as the azeotrope with toluene. The solution was cooledslightly below the boiling point and one mole (134 grams) of diethyleneglycol monoethyl ether was added. Heating was resumed until another mole(18 ml.) of water was removed from the reaction mixture. Again thesolution was cooled below the boiling point and one mole (120 grams) ofdiethylene glycol monomethyl ether was added. The solution was heated toboiling and a third mole (18 ml.) of water was removed following whichthe toluene remaining in the reaction mixture was removed to yield a triborate ester of the fonnula:

The reflux boiling pint (dry) of the ester was 610F. at atmosphericpressure and it exhibited a viscosity of 775 cs. at 40F.

Percent B Analysis:

Calculated: 2.58 Found: 2.83

EXAMPLE 10 Percent by Weight Borate Ester E (Described below) 29.18[CH,,(OCH,CH,),O] -,-B 55.48 Triethylene glycol monomethyl ethe 1 l .90Diethanolamine 0.91 Polyethylene glycol (Mol. wt. 300 2.52 Sodiumnitrite 0.01 Total 100.00

Properties:

Reflux boiling point (dry) at atmospheric pressure Reflux boiling point(wet) at atmospheric pressure of 3.5 parts by volume of water and 100parts by volume of fluid of Example 383F.

Viscosity 40F. 2380 cs.

212F. 3.38 cs. Water Tolerance Test Passed water tolerance test at 40F.and 140F. ac-

cording to procedure of SAE .l70c.

Borate Ester E employed in the above fluid composition, which is a Type111 borate ester, was prepared as follows: One mole (354 grams) of arandom addition product of ethylene oxide and propylene oxide with butylalcohol, prepared by reaction a mixture containing weight percentethylene oxide and 50 weight percent propylene oxide with the alcohol,and ml. of toluene were mixed with one-third mole (20 grams) oforthoboric acid. The mixture was heated to its boiling point and onemole (18 ml.) of water was removed as the azeotrope with toluene afterwhich the toluene remaining in the reaction mixture was removed undervacuum. The resulting tris borate ester (Borate Ester E) was clear,water-white liquid having a reflux boiling point (dry) of approximately625 30F.

EXAMPLE 1 1 Percent by Weight IQ A C z Ofih- Triethylene glycolmonoethyl ether l2.78 Methyldiethanolamine 2.20 Polyethylene glycol(Mol. wt. 300) 5.00 Diisopropyl ammonium nitrite 0.02 Total 100.00

EXAMPLE 12 Percent by Weight [C H,(OCH,CH,),O],-B 70.30 Trlethyleneglycol monomethyl ether 19.95 'Diethanolamine 1.85 Polyethylene glycol(Mol. wt. 300) 7.85 Di(2-ethylhexyl) ammonium nitrite 0.05 Total 100.00

EXAMPLE 13 Percent by Weight [C H,(OCH,CH9)1O],-B 66.00 Tnethyleneglycol monomethyl ether 25.90 Diethanolamine 1.85 Polyethylene glycol(Mol. wt. 300) 6.00 Benzotriazole 0.25 Total 100.00

EXAMPLE 14 Percent by Weight [C ,H (0CH CH,),O] -B 80.00 Tnethyleneglycol monoethyl ether 15.0 Polyethylene glycol (Mol. wt. 300) 5.0 Total100.00

EXAMPLE 15 Percent by Wei ht [C H,(OCH,CH,) O] -,-B g 67.40 Tr iethyleneglycol monomethyl ether 25.81 Diethanolamine 1.711 Polyethylene glycol(Mol. wt. 300) 5.00 Sodium Nitrite 0.01 Total 100.00

E X A M PL E 1 6 Percent by Wei ht CH (0CH,CHz)a0];-B g 75.00Trlethylene glycol monomethyl ether 6.20 Tetraethylene glycol monoethylether 17.00 Diethanolamine 1.68 Sodium Nitrite 0.02 Tolutriazole 0.10Total 100.00

is shown below:

Properties of Water lnsensitive Brake Fluid of Example LE 21 Percent byWeight a( 2)a ]s- 75.00 rttethylletie glytiol nltonomethyg1 etherI l1.25 e rae y ene g yco monome et er 12.00 Test Diethyl aminoethoxyethanol 1.75 Test SAEJ I702 Results 100110 EXAMPLE 22 Refluxboiling point (dry) 374F. min. 532F. 1O 513th point 2 2 7 9.61 min.320%. mfg: by

iscosity at 1 F. cs. min. 2.5 cs. [CH (OCH CH Q] .B 7090 Viscosity at40F. 1800 cs. max. 1530 cs. Trietfhylene glyol monomethyl ether 13.257.0 to l 1.5 7.5 Tetraethylene glycol monomethyl ether 15.00 Evaporattonloss 80 percent max., 62 percent biejhyl gghgnglamine 1 .75 M Total100.00 EXAMPLE 17 EXAMPLE 23 Percent by Weight Percent by[Cl-l,(OCH,Cl-l,),O],-B 70.00 Weight Tetraethylene glycol monoethylether 21 .00 '[CH,(OCH,CH,),O],-B 72.00 Triethylene glycol monomethylether 7.20 Triethylene glycol monoethyl ether 16.25 Diethanolamine 1.68Tetraethylene glycol monoethyl ether 10.00 Tolutriazole 0. l 0Hydroxyethyl hydrazine 1 ,75 Sodium Nitrite 1 Total 100.00

Total EXAMPLE 24 Reflux boilin oint dr at atmos heric ressure o g p y) pp 25. Percent by 528 F. weigh! V|scos1ty at 40F. 1447 cs. a( :)a l J'B66. p 7 3 :lr etgylene glycol monoethyl elthel: 5.00 net yenegycomonomet y et er 17.00 EXAMPLE 8 'lgetraethylene gllylgcol monomethylether 10.00 let y aminoe anol 2.00 Total 100.00 Percent by WeightEXAMPLE 25 ICH,(OCH,CHi),OI]=,-B m i u Tetraethylene g yco monoe y e erTriethylene glycol monomethyl ether 522m by Diethanolamine l. CH B 73 0ODietl tylene glycttl mo noethyl ether 5.00 Sodmm f m1 loo-00 Triethyleneglycol monomethyl ether 10.00 0 Tetraethylene glycol monomethyl ether10.00 I Dtmethyl amino ethoxyethanol 2.00 Reflux boiling point (dry) atatmospheric pressure 528F.

EXAMPLE 26- viscosity at 40F. 1552 cs. pH 7,35 Percent by [CH (OCH CH)0] B weight 73.20 EXAMPLE Trieihylenglyol monomethyl ether 10.00Percent y Eetrgethylene glycol monomethyl ether 15.00 let ano amine v v1.78 Weight cH, 0cH,cH, ,01,-B 66.00 f 885 Tetraethylenel glyfolmonoettgtygl etter Triethylenegyco monome y et er Diethanolarnine 1.68EXAMPLE 27 Tolutriazole 0. l 0 Sodium Nitrite 0.02 Percent by Total100.00 Weight [CH,(OCH,CH2)=O] -B 75.00 Triethylene glycol monomethylether 6.00 Reflux botlmg pomt (dry) at atmospheric pressure Triethyleneglycol monoethyl ether 7.00 o Tetraethylene glycol monoethyl ether 10.00526 o Hydroxyethyl hydrazine 1.90 VlSCOSlty at F. CS. Tohn iazole 0 |0pH 7.5 Total 100.00

EXAMPLE 20 EXAMPLE 28 Percent by Percent by Weight WeightICH,(OCH,CH,),OI J 75.00 ICHAQCHICHQIOII'B Tetraethylene glycolmonoethyl ether 23.20 Tnethylene glycol monomflhyl ether DiethanoamineL68 gtiatt'zethyilcne glycol monomethyl ether 1' 1 t .01 0.10 1 s d i ulit l lit rite 0.02 8'8;

T t l .00

a Total 100.00 Reflux boiling point (dry) at atmospheric pressureEXAMPLE 29 535F.

Viscosity at -40F. 1663 Pe F by Weight 1 1(OCH;C )a ]r Triethyleneglycol monomethyl ether Triethylene glycol monoethyl ether Tetraethyleneglycol monoethyl ether Hydroxyethyl hydrazine Tolutriazole Total EXAMPLE30 2 5( z z): ]3' Triethylene glycol monomethyl ether Triethylene glycolmonoethyl ether Tetraethylene glycol monoethyl ether Hydroxyethylhydrazine Tolutriazole Total EXAMPLE 31 Tripropylene glycol dimethylether Nethyl morpholine Polyethylene glycol (Mol. wt. 250) Total EXAMPLE32 Triethylene glycol monoethyl ether Triethylene glycol monomethylether Mixed isopropanolamines (-1 5% mono,

40-50% di, 4050% tri) Glycerin Butynediol Dioctyl diphenylamine Sodiumnitrite Total Properties:

Reflux boiling point (dry) Reflux boiling point (wet) (3.5 ml. water 100ml. fluid) Viscosity at 40F.

EXAMPLE 33 2 5( z z):i ]a' z s( 2)4 ]a' Triethylene glycol monoethylether Diethylene glycol monomethyl ether Mixed isopropanolamines (IO-%mono, 40-50% di, 40-50% tri) Glycerin Butynediol Dioctyl diphenylamineSodium nitrite Total Properties:

Reflux boiling point (dry) Reflux boiling point (wet) (3.5 ml. water+100 ml. fluid) Viscosity at 40F.

EXAMPLE 34 Triethylene glycol monoethyl ether Diethylene glycolmonoethyl ether Mixed isopropanolamines (IO-15% mono,

40-60% tri) Glycerin Butynediol Dioctyl diphenylamine Sodium nitritePercent by Weight Percent by Weight Percent by Weight Percent by WeightPercent by Weight 343F. 1961 cs.

342F. 1542 cs.

Properties:

Reflux boiling point (dry) Reflux boiling point (wet) (3.5 ml. water+100 ml. fluid) Viscosity at -40F.

EXAMPLE 3 5 Properties: 0

Reflux boiling point (dry) Reflux boiling point (wet) (3.5 ml. water+100 ml. fluid) Viscosity at 40F.

25 EXAMPLE 36 [CH3(OCH2CH!)30]3'B Tetraethylene glycol monoethyl etherTriethylene glycol monomethyl ether Monoethanolamine BenzotriazoleDiisopropanolamine nitrite Total Properties:

Reflux boiling point (dry) Reflux boiling point (wet) (3.5 ml. water 100ml. fluid) Viscosity at F.

40 EXAMPLE 37 1 2 2):1 ]a' Tetraethylene glycol monoethyl etherTriethylene glycol monomethyl ether Monoethanolamine BenzotriazoleDiisopropanolamine nitrite Total Properties:

Reflux boiling point (dry) Reflux boiling point (wet) (3.5 ml. water+100ml. fluid) Viscosity at -40F.

EXAMPLE 38 a( z z):| ]:r Tetraethylene glycol monoethyl etherTriethylene glycol monomethyl ether Monoethanolamine BenzotriazoleDiisopropanolamine nitrite Total 5 Properties:

Reflux boiling point (dry) Reflux boiling point (wet) (3.5 ml. water+ml. fluid) Viscosity at 40F.

Percent by Weight Percent by Weight Percent by Weight Percent by Weight323F. 373 cs.

334F. 1585 cs.

340F. 584 cs.

332F. 456 cs.

EXAMPLE 39 Mixed isopropanolamine (lo-45% mono,

40-50% di. 40-50% tri) Glycerin Butynediol Dioctyl diphenylamine( VanLube 81 produced by R.T.Vanderbilt Co.) Sodium nitrite Total Properties:

Reflux boiling point (dry) Reflux boiling point (wet) (3.5 ml. water+100 ml. fluid) Viscosity at 40F.

EXAMPLE 40 Triethylene Glycol monomethyl ether DiethanolaminePolyethylene glycol (M.W. 300) Sodium nitrite Total Properties:

Reflux boiling point (dry) Reflux boiling point (wet) (3.5 ml. water100ml. fluid) EXAMPLE 41 Triethylene glycol monomethyl etherDiethanolamine Polyethylene glycol (M.W. 300) Sodium nitrite TotalProperties:

Reflux boiling point (dry) Reflux boiling point (wet) (3.5 ml; water+100 ml. fluid) EXAMPLE 42 Triethylene glycol monomethyl etherDiethanolamine Polyethylene glycol (M.W. 300) Sodium nitrite TotalProperties:

Reflux boiling point (dry) Reflux boiling poin t(wet) (3.5 ml. water+100 ml. fluid) EXAMPLE 43 Percent by Weight Percent by Weight Percent byWeight Percent by Weight 373F. 2453 cs.

A hydraulic fluid having the following composition was prepared:

Percent by Weight lsoctanol 2 Monoethanolamine Total cos Properties:

Reflux boiling point (dry) 463F. Reflux boiling point (wet) (3.5 ml.water ml. fluid) Viscosity at -40F.

310F. 816 cs.

EXAMPLE 44 A hydraulic fluid having the following composition wasprepared:

Percent by Weight [CH,(OCH,CH,);,O],,-B 79.0 Hexylene glycol 20.0Monoethanolamine 1.0 Total 100.0

Properties:

Reflux boiling point (dry) 489F. Reflux boiling point (wet) (3.5 ml.water +100 ml. fluid) 343F. Viscosity at 40F.

EXAMPLE 45 A hydraulic fluid having the following composition wasprepared:

What is claimed is:

l. A hydraulic fluid composition consisting essentially of (A) fromabout 20 to about 54.4 percent by weight, based on the total weight ofthe hydraulic fluid composition of at least one base fluid or lubricantselected from the group consisting of (a) a borate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, R, is alkylene offrom two to four carbon atoms and y is an integer of from two to four;(b) a borate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, R and R areindependently selected from the group consisting of hydrogen and methyl,m and n are positive integers whose sum is from 2 to 20, and with theproviso that one of R and R is methyl and one of R, and R is hydrogen;(0) a borate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, Rg is a hetericoxyalkylene chain of the formula:

25 Z UQ 2 3),'I

wherein the sum of r and s is not more than 20 and wherein the weightpercent of the oxyethylene units is not less than 20 based on the totalweight of all the oxyalkylene units; and (d) a borate ester of theformula:

wherein T,, T, and T are each an independently selected alkyl grouphaving from one to four carbon atoms; R R R R R and R are independentlyselected from the group consisting of hydrogen and methyl, n and m arepositive integers independently selected in each chain and whose sum ineach chain is from 2 to 20, and with the proviso that in no more thantwo of the chains is the sum of n and m the same; and the remainder ofthe hydraulic fluid composition comprising: (B) from 0 to about 80percent by weight, based on the total weight'of the fluid composition,of at least one diluent selected from the group consisting of: (i)glycol ethers having the formula:

wherein R is alkyl of from one to four carbon atoms, R is selected fromthe group consisting of hydrogen and alkyl of from one to four carbonatoms, R" is alkylene of from two to four'carbon atoms and y is aninteger of from 2 to 4; (ii) glycols and polyglycols having a molecularweight of from about 60 to about 450 and (iii) aliphatic saturated,monohydric alcohols having from six to 13 carbon atoms.

'2. A hydraulic fluid composition consisting essentially of (A) fromabout 20 to about 54.4. percent by weight, based on the total weight ofthe hydraulic fluid composition of at least one base fluid or lubricantselected from the group consisting of (a) a borate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, R,, is alkylene offrom two to four carbon atoms and y is an integer of from 2to 4; (b) aborate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, R and R areindependently selected from the group consisting of hydrogen and methyl,m and'n are positive integers whose sum is from 2 to 20, and with theproviso that one of R and R is methyl and one of R and R is hydrogen;(0) a borate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, Rg is a hetericoxyalkylene chain of the formula:

wherein the sum of r and s is not more than 20 and wherein the weightpercent of the oxyethylene units is not less than 20 based on the totalweight of all the oxyalkylene units; and (d) a borate ester of theformula:

wherein T,, T and T are each an independently selected alkyl grouphaving from one to four carbon atoms; R R R R-,, R and R areindependently selected from the group consisting of hydrogen and methyl,n andm are positive integers independently selectedin each chain andwhose sum in each chain is from 2 to 20, and with the proviso that in nomore than two of the chains is the sum of n and m the same; and theremainder of the hydraulic fluid composition comprising: (B) from 0 toabout percent by weight, based on the total weight of the fluidcomposition, of at least one diluent selected from the group consistingof: (i) glycol ethers having the formula:

wherein R is alkyl of from one to four carbon atoms, R' is selected fromthe group consisting of hydrogen and alkyl of from one to four carbonatoms, R is alkylene of from two to four carbon atoms and y is aninteger of from 2 to 4; (ii) glycols and polyglycols having a molecularweight of from about 60 to about 450 and (iii) aliphatic saturated,monohydric alcohols having from six to 13 carbon atoms and (C) from 0 toabout 10.0 percent by weight, based on the total weight of the hydraulicfluid, of at least one inhibitor for pH and corrosion control.

3'. A hydraulic fluid composition consisting essentially of (A) fromabout 20 to about 54.4 percent by weight, based on the total weight ofthe hydraulic fluid composition of at least one base fluid or lubricantselected from the group consisting of (a) a borate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, R,, is alkylene offrom two to four carbon atoms and y is an integer of from 2 to 4; (b) aborate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, R and R areindependently selected from the group consisting of hydrogen and methyl,m and n are positive integers whose sum is from 2 to 20, and with theproviso that one of R and R is methyl and one of R and R is hydrogen;(c) a borate ester of the formula: 1[ g] )rwherein R, is alkyl of fromone to four carbon atoms, Rg is a heteric oxyalkylene chain of theformula:

wherein the sum of r and s is not more than 20 and wherein the weightpercent of the oxyethylenc units in not less than 20 based on the totalweight of all the oxyalkylene units; and (d) a borate ester of thefor-mula:

/O(RtCHCHa0) (R CHCHgO) T B-O(RQCHCHQO)n(R1CHCHzO)mT2 \O(RQCHCILO),,(ROHCH2O)mTs wherein T,, T and T are each an independently selected alkylgroup having from one to four carbon atoms; R,, R R R R and R areindependently selected from the group consisting of hydrogen and methyl,n and m are positive integers independently selected in each chain andwhose sum in each chain is from 2 to 20, and with the proviso that in nomore than two of the chains is the sum of n and m the same; and

the remainder of the hydraulic fluid composition comprising: (B) from toabout 80 percent by weight, based on the total weight of the fluidcomposition, of at least one diluent selected from the group consistingof: (i) glycol ethers having the formula:

' "Rio-R"1,oR',

wherein R is alkyl of from one to four carbon atoms, R is selected fromthe group consisting of hydrogen and alkyl of from one to four carbonatoms, R" is alkylene of from 2 to 4 carbon atoms and y is an integer offrom 2 to 4; (ii) glycols and polyglycols having a molecular weight offrom about 60 to about 450 and (iii) aliphatic saturated, monohydricalcohols having from six to 13 carbon atoms and (C) from 0 to about 10.0percent by weight, based on the total weight of the hydraulic fluid, ofat least one antioxidant.

4. A hydraulic fluid composition consisting essentially of (A) fromabout 20 to about 54.4 percent by weight, based on the total weight ofthe hydraulic fluid composition of at least one base fluid or lubricantselected from the group consisting of (a) a borate ester of the formulawherein R is alkyl of from one to four carbon atoms, R, is alkylene offrom two to four carbon atoms and y is an integer of from 2 to 4; (b) aborate ester of the fortm laa [R (OCH' CHR ),,,--(OCH CHR ),,O] B

wherein R is alkyl of from one to four carbon atoms, R and R areindependently selected from the group consisting of hydrogen and methyl,m and n are positive integers whose sum is from 2 to 20, and with theproviso that one of R and R is methyl and one of R and R is hydrogen;(c) a borate ester of the formula:

( 1l gl )3' wherein R is alkyl of from one to four carbon atoms, Rg is aheteric oxyalkylene chain of the formula:

wherein the sum of r and s is not more than 20 and wherein the weightpercent of the oxyethylene units is not less than 20 based on the totalweight of all the oxyalkylene units; and (d) a borate ester of theformula:

the remainder of the hydraulic fluid composition comprising: (B) from 0to about 80 percent by weight, based on the total weight of the fluidcomposition, of at least one diluent selected from the group consistingof: (i) glycol ethers having the formula:

1 wherein R is alkyl of from one to four carbon atoms, R is selectedfrom the group consisting of hydrogen and alkyl of from one to fourcarbon atoms, R" is alkylene of from two to four carbon atoms and y isan integer of from 2 to 4; (ii) glycols and polyglycols having amolecular weight of from about 60 to about 450 and (iii) aliphaticsaturated, monohydric alcohols having from six to 13 carbon atoms and(C) from 0 to about 10.0 percent by weight, based on the total weight ofthe hydraulic fluid, of at least one rust inhibitor.

5. A hydraulic fluid composition consisting essentially of (A) fromabout 20 to about 54.4 percent by weight, based on the total weight ofthe hydraulic fluid composition of at least one base fluid or lubricantselected from the group consisting of (a) a borate ester of the formula:

wherein R is alkyl of from one to four carbon atoms, R, is alkylene offrom two to four carbon atoms and y is an integer of from 2 to 4; (b) aborate ester of the formula:

"""(RllR ioia ia wherein R is alkyl of from one to four carbon atoms.

Rg is a heteric oxyalkylene chain of the formula:

wherein the sum of r and s is not more than 20 and wherein the weightpercent of the oxyethylene units is not less than 20 based on the totalweight of all the oxyalkylene units; and (d) a borate ester of theformula:

wherein T T and T are each in independently selected alkyl group havingfrom one to four carbon atoms; R R R R R and R are independentlyselected from the group consisting of hydrogen and wherein R is alkyl offrom one to four carbon atoms, R is selected from the group consistingof hydrogen and alkyl of from one tofour carbon atoms, R is alkylene offrom two to four carbon atoms and y is an integer of from 2 to 4; (ii)glycols and polyglycols having a molecular weight of from about 60 toabout 450 and (iii) aliphatic saturated, monohydric alcohols havingmethyl, n and m are positive integers independently,

from six to 13 carbon atoms and (C) from O to about l0.0 percent byweight, based on the total weight of the hydraulic fluid, of at leastone viscosity index improver.

6. A hydraulic fluid composition consisting essentially of (A) fromabout 20 to about 54.4 percent by weight, based on the total weight ofthe hydraulic fluid composition of at least one base fluid or lubricantselected from the group consisting of (a) a borate ester ofthe formula:

wherein R, is alkyl of from one to four carbon atoms, R,, is alkylene offrom two to four carbon atoms and y is an integer of from 2 to 4; (b) aborate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, R and R areindependently selected from the group consisting of hydrogen and methyl,m and n are positive integers whose sum is from 2 to 20, and with theproviso that one of R and R is methyl and one of R and R is hydrogen; aborate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, Rg is a hetericoxyalkylene chain of the formula:

wherein the sum of r and s is not more than and wherein the weightpercent of the oxyethylene units is not less than 20 based on the totalweight of all the oxyalkylene units; and (d) a borate ester of theformula:

Omassage)ma mas, B-O(RQGHCH2O) (R1CHCH2O)mT2 \O(RsCHCHzOM-(R CHCHQOMT;

wherein T,, T and T are each an independently selected alkyl grouphaving from one to four carbon atoms; R,, R R R R and R areindependently selected from the group consisting of hydrogen and whereinR is alkyl of from one to four carbon atoms, R is selected from thegroup consisting of hydrogen and alkyl of from one to four carbon atoms,R" is alkylene of from two to four carbon atoms and y is an integer offrom 2 to 4; (ii) glycols and polyglycols having a molecular weight offrom about 60 to about 450 and (iii) aliphatic saturated, monohydricalcohols having from six to 13 carbon atoms and (C) from 0 to about 10.0percent by weight, based on the total weight of the hydraulic fluid, ofat least one pour point depressant.

7. A hydraulic fluid composition consisting essen tially of (A) fromabout 20 to about 54.4 percent by weight, based on the total weight ofthe hydraulic fluid composition of at least one base fluid or lubricantselected from the group consisting of (a) a borate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, R,, is alkylene offrom two to four carbon atoms and y is an integer of from 2 to 4; (b) aborate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, R and R areindependently selected from the group consisting of hydrogen and methyl,m and n are positive integers whose sum is from 2 to 20, and with theproviso that one of R and R is methyl and one of R and R is hydrogen;(c) a borate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, Rg is a hetericoxyalkylene chain of the formula:

wherein the sum of r and s is not more than 20 and wherein the weightpercent of the oxyethylene units is not less than 20 based on the totalweight of all the oxyalkylene units; and (d) a borate ester of theformula:

o(aiottcmo)wmtcaoalo r, B-0(R0011oHi0)n(R1oHoH10)mT,\0(R8CHCH20)n(R9CHCH20)mT3 wherein T,, T and T are each an independentlyselected alkyl group having from one to four carbon atoms; R.,, R R R Rand R are independently selected from the group consisting of hydrogenand methyl, n and m are positive integers independently selected in eachchain and whose sum in each chain is from 2 to 20, and with the provisothat in no more than two of the chains is the sum of n and m the same;and the remainder of the hydraulic fluid composition comprising: (B)from 0 to about percent by weight, based on the total weight of thefluid composition, of at least one diluent selected from the groupconsisting of: (i) glycol ethers having the formula:

wherein R is alkyl of from one to four carbon atoms, R is selected fromthe group consisting of hydrogen and alkyl of from one to four carbonatoms, R" is alkylene of from two to four carbon atoms and y is aninteger of from 2 to 4; (ii) glycols and polyglycols having a molecularweight of from about 60 to about 450 and (iii) aliphatic. saturated,monohydric alcohols having from six to 13 carbon atoms and (C) from 0 toabout 10.0 percent by weight, based on the total weight of the hydraulicfluid, of at least one lubricity agent.

8. A hydraulic fluid composition consisting essentially of (A) fromabout 20 to about 54.4 percent by weight, based on the total weight ofthe hydraulic fluid composition of at least one base fluid or lubricantselected from the group consisting of (a) a borate ester of the formula:

- [R,(O-R,, ),,O],-B wherein R, is alkyl of from one to four carbonatoms, R, is alkylene of from two to four carbon atoms and y is aninteger offrom 2 to 4; (b) a borate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, Rg is a hetericoxyalkylene chain of the formula:

(OCH CH (OCH CHCHQ, wherein the sum ofr and s is not more than 20 andwherein the weight percent of the oxyethylene units is not less than 20based on the total weight of all the oxyalkylene units; and (d) a borateester of the formula:

wherein T,, T and T are each an independently selected alkyl grouphaving from one to four carbon atoms; R,, R R R R and R areindependently selected from the group consisting of hydrogen and methyl,n and m are positive integers independently selected in each chain andwhose sum in each chain is from 2 to 20, and with the proviso that in nomore than two of the chains is the sum of n and m the same; and theremainder of the hydraulic fluid composition comprising: (B) from 0 toabout 80 percent by weight, based on the totalweight of the fluidcomposition, of at least one diluent selected from the group consistingof: (i) glycol ethers having the formula:

wherein R is alkyl of from one to four carbon atoms, R is selected fromthe group consisting of hydrogen and alkyl of from one to four carbonatoms, R" is alkylene of from two to four carbon atoms and y is aninteger of from 2 to 4; (ii) glycols and polyglycols having a molecularweight of from about 60 to about 450 and (iii) aliphatic saturated,monohydric alcohols having from six to 13 carbon atoms and (C) from 0 toabout 10.0 percent by weight, based on the total weight of the hydraulicfluid, of at least one dye.

9. The hydraulic fluid composition of claim 2 which contains from 0 toabout 8.0 percent by weight of at least one said inhibitor for pH andcorrosion control and from 0 to about 2.0 percent by weight of at leastone antioxidant.

10. The hydraulic fluid composition of claim 2 wherein said base fluidor lubricant is at least one borate ester of type (a). I

11. The hydraulic fluid composition of claim wherein said diluentis oftype (i).

12. The hydraulic fluid composition of claim 11 which contains fromabout 0.2 to about 6.0 percent by weight, based on the total weight ofthe hydraulic fluid, of at least one said inhibitor for pH and corrosioncontrol.

13. The hydraulic fluid composition of claim 12 which contains fromabout 0.001 to about 1.0 percent by weight, based on the total weight ofthe hydraulic fluid, of at least one said antioxidant.

14. The hydraulic fluid composition of claim 2 wherein said base fluidor lubricant consists essentially of from about 30 to about 54.4 percentby weight, based on the total weight of the hydraulic fluid composition.

15. The hydraulic fluid composition of claim 14 wherein said base fluidor lubricant is at least one borate ester of type (a).

16. The hydraulic fluid composition of claim 15 wherein said borateester of type (a) has an R, alkyl group of one to two carbon atoms andan R, alkylene group of2 to 3.

17. The hydraulic fluid composition of claim 15 wherein said borateester of type (a) is selected from the group consisting of ICH,,(OCH CHO] -B, [C H,, CH O] -B, [C H (OCH CH O] B, 2 nr "2 2)4 ]3' 3 1( 2 2)3 ]34 a.l 2 2)2 ]3 v and 4 9( 2 2)s 01 -8.

18. The hydraulic fluid composition of claim 15 wherein said diluent isat least one glycol ether of type (i).

19. The hydraulic fluid composition of claim 18 wherein said glycolether of type (i) has an alkyl R group of one to two carbon atoms, an Rselected from the group consisting of hydrogen and alkyl of one to twocarbon atoms and an alkylene R" group of from two to three carbon atoms.

20. The hydraulic fluid composition of claim 18 wherein said glycolether is selected from the group consisting of diethylene glycolmonomethyl ether, diethylene glycol monoethyl ether, diethylene glycolmonobutyl ether, triethylene glycol monomethyl ether, triethylene glycolmonoethyl ether, triethylene glycol monobutyl ether, tetraethyleneglycol monomethyl ether and tetraethylene glycol monobutyl ether.

21. The hydraulic fluid composition of claim 18 which contains fromabout 0.2 to about 6.0 percent by weight, based on the total weight ofthe hydraulic fluid of at least one inhibitor for pH and corrosioncontrol.

22. The hydraulic fluid composition of claim 21 which contains fromabout 0.001 to about 1.0 percent by weight, based on the total weight ofthe hydraulic fluid, of at least one antioxidant.

23. In the operation of a fluid pressure operating device which useshydraulic pressure transmission fluid, the improvement comprising usingas said hydraulic pressure transmission fluid a composition consistingessentially of from about 20 to about 54.4 percent by weight, basedon-the total weight of the hydraulic fluid composition, of at least oneborate ester base fluid or lubricant selected from the group consistingof (a) a borate ester of the formula:

l( a) ]8 wherein R, is alkyl of from one to four carbon atoms, R, isalkylene of from two to four carbon atoms and y is an integer of from 2to 4; (b) a borate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, Rg is a hetericoxyalkylene chain of the formula:

[ z UT 2 3)s wherein the sum of r and s is not more than 20 and whereinthe weight percent of the oxyethylene units is not less than 20 based onthe total weight of all the oxyalkylene units; and (d) a borate ester ofthe formula:

/0(1ucuc1r2 ).,(luclrcmom' i 13-0(mencm0).,-(R10Hcm0)m'li \O(RBCIiC20)n"'(RDCIICII20)mTS wherein T T and T are each an independentlyselected alkyl group having from one to four carbon atoms; R.,, R R R-,,R and R are independently selected from the group consisting of hydrogenand methyl, n and m are positive integers independently selected in eachchain and whose sum in each chain is from 2 to 20, and with the provisothat in no more than two of the chains is the sum of n and m the same.

24. The process of claim 23 wherein there is from about 30 to about 54.4percent by weight, based on the total weight of the hydraulic fluidcomposition, of said base fluid or lubricant.

25. The process of claim 24, wherein said base fluid or lubricantincludes at least one borate ester of type (a).

2. A hydraulic fluid composition consisting essentially of (A) fromabout 20 to about 54.4 percent by weight, based on the total weight ofthe hydraulic fluid composition of at least one base fluid or lubricantselected from the group consisting of (a) a borate ester of the formula:(R1(O-Ra)y-O)3-B , wherein R1 is alkyl of from one to four carbon atoms,Ra is alkylene of from two to four carbon atoms and y is an integer offrom 2 to 4; (b) a borate ester of the formula:(R1-(OCH2CHR2)m-(OCH2CHR3)nO)3-B , wherein R1 is alkyl of from one tofour carbon atoms, R2 and R3 are independently selected from the groupconsisting of hydrogen and methyl, m and n are positive integers whosesum is from 2 to 20, and with the proviso that one of R2 and R3 ismethyl and one of R2 and R3 is hydrogen; (c) a borate ester of theformula: (R1(Rg)O)3-B, wherein R1 is alkyl of from one to four carbonatoms, Rg is a heteric oxyalkylene chain of the formula: (- (OCH2CH2)r ,(OCH2CHCH3)s -) , wherein the sum of r and s is not more than 20 andwherein the weight percent of the oxyethylene units is not less than 20based on the total weight of all the oxyalkylene units; and (d) a borateester of the formula:
 3. A hydraulic fluid composition consistingessentially of (A) from about 20 to about 54.4 percent by weight, basedon the total weight of the hydraulic fluid composition of at least onebase fluid or lubricant selected from the group consisting of (a) aborate ester of the formula: (R1)O-Ra)y-O)3-B , wherein R1 is alkyl offrom one to four carbon atoms, Ra is alkylene of from two to four carbonatoms and y is an integer of from 2 to 4; (b) a borate ester of theformula: (R1-(OCH2CHR2)m-(OCH2CHR3)nO)3-B , wherein R1 is alkyl of fromone to four carbon atoms, R2 and R3 are independently selected from thegroup consisting of hydrogen and methyl, m and n are positive integerswhose sum is from 2 to 20, and with the proviso that one of R2 and R3 ismethyl and one of R2 and R3 is hydrogen; (c) a borate ester of theformula: (R1(Rg)O)3-B, wherein R1 is alkyl of from one to four carbonatoms, Rg is a heteric oxyalkylene chain of the formula:(- (OCH2CH2)r ,(OCH2CHCH3)s -) , wherein the sum of r and s is not more than 20 andwherein the weight percent of the oxyethylene units in not less than 20based on the total weight of all the oxyalkylene units; and (d) a borateester of the formula:
 4. A hydraulic fluid composition consistingessentially of (A) from about 20 to about 54.4 percent by weight, basedon the total weight of the hydraulic fluid composition of at least onebase fluid or lubricant selected from the group consisting of (a) aborate ester of the formula: (R1(O-Ra)y-O)3-B , wherein R1 is alkyl offrom one to four carbon atoms, Ra is alkylene of from two to four carbonatoms and y is an integer of from 2 to 4; (b) a borate ester of theformula: (R1-(OCH2CHR2)m-(OCH2CHR3)nO)3-B , wherein R1 is alkyl of fromone to four carbon atoms, R2 and R3 are independently selected from thegroup consisting of hydrogen and methyl, m and n are positive integerswhose sum is from 2 to 20, and with the proviso that one of R2 and R3 ismethyl and one of R2 and R3 is hydrogen; (c) a borate ester of theformula: (R1(Rg)O)3-B, wherein R1 is alkyl of from one to four carbonatoms, Rg is a heteric oxyalkylene chain of the formula:(- (OCH2CH2)r ,(OCH2CHCH3)s -) , wherein the sum of r and s is not more than 20 andwherein the weight percent of the oxyethylene units is not less than 20based on the total weight of all the oxyalkylene units; and (d) a borateester of the formula:
 5. A hydraulic fluid composition consistingessentially of (A) from about 20 to about 54.4 percent by weight, basedon the total weight of the hydraulic fluid composition of at least onebase fluid or lubricant selected from the group consisting of (a) aborate ester of the formula:(R1(O-Ra)y-O)3-B , wherein R1 is alkyl offrom one to four carbon atoms, Ra is alkylene of from two to four carbonatoms and y is an integer of from 2 to 4; (b) a borate ester of theformula: (R1-(OCH2CHR2)m-(OCH2CHR3)nO)3-B , wherein R1 is alkyl of fromone to four carbon atoms, R2 and R3 are independently selected from thegroup consisting of hydrogen and methyl, m and n are positive integerswhose sum is from 2 to 20, and with the proviso that one of R2 and R3 ismethyl and one of R2 and R3 is hydrogen; (c) a borate ester of theformula: (R1(Rg)O)3-B, wherein R1 is alkyl of from one to four carbonatoms, Rg is a heteric oxyalkylene chain of the formula:(-(OCH2CH2)r ,(OCH2CHCH3)s -) , wherein the sum of r and s is not more than 20 andwherein the weight percent of the oxyethylene units is not less than 20based on the total weight of all the oxyalkylene units; and (d) a borateester of the formula:
 6. A hydraulic fluid composition consistingessentially of (A) from about 20 to about 54.4 percent by weight, basedon the total weight of the hydraulic fluid composition of at least onebase fluid or lubricant selected from the group consisting of (a) aborate ester of the formula: (R1(O-Ra)y-O)3-B , wherein R1 is alkyl offrom one to four carbon atoms, Ra is alkylene of from two to four carbonatoms and y is an integer of from 2 to 4; (b) a borate ester of theformula: (R1-(OCH2CHR2)m-(OCH2CHR3)nO)3-B , wherein R1 is alkyl of fromone to four carbon atoms, R2 and R3 are independently selected from thegroup consisting of hydrogen and methyl, m and n are positive integerswhose sum is from 2 to 20, and with the proviso that one of R2 and R3 ismethyl and one of R2 and R3 is hydrogen; (c) a borate ester of theformula: (R1(Rg)O)3-B, wherein R1 is alkyl of from one to four carbonatoms, Rg is a heteric oxyalkylene chain of the formula: (- (OCH2CH2)r ,(OCH2CHCH3)s -) , wherein the sum of r and s is not more than 20 andwherein the weight percent of the oxyethylene units is not less than 20based on the total weight of all the oxyalkylene units; and (d) a borateester of the formula:
 7. A hydraulic fluid composition consistingessentially of (A) from about 20 to about 54.4 percent by weight, basedon the total weight of the hydraulic fluid composition of at least onebase fluid or lubricant selected from the group consisting of (a) aborate ester of the formula: (R1(O-Ra)y-O)3-B , wherein R1 is alkyl offrom one to four carbon atoms, Ra is alkylene of from two to four carbonatoms and y is an integer of from 2 to 4; (b) a borate ester of theformula: (R1-(OCH2CHR2)m-(OCH2CHR3)nO)3-B , wherein R1 is alkyl of fromone to four carbon atoms, R2 and R3 are independently selected from thegroup consisting of hydrogen and methyl, m and n are positive integerswhose sum is from 2 to 20, and with the proviso that one of R2 and R3 ismethyl and one of R2 and R3 is hydrogen; (c) a borate ester of theformula: (R1(Rg)O)3-B, wherein R1 is alkyl of from one to four carbonatoms, Rg is a heteric oxyalkylene chain of the formula: (- (OCH2CH2)r ,(OCH2CHCH3)s -) , wherein the sum of r and s is not more than 20 andwherein the weight percent of the oxyethylene units is not less than 20based on the total weight of all the oxyalkylene units; and (d) a borateester of the formula:
 8. A hydraulic fluid composition consistingessentially of (A) from about 20 to about 54.4 percent by weight, basedon the total weight of the hydraulic fluid composition of at least onebase fluid or lubricant selected from the group consisting of (a) aborate ester of the formula: (R1(O-Ra)y-O)3-B , wherein R1 is alkyl offrom one to four carbon atoms, Ra is alkylene of from two to four carbonatoms and y is an integer of from 2 to 4; (b) a borate ester of theformula: (R1-(OCH2CHR2)m-(OCH2CHR3)nO)3-B , wherein R1 is alkyl of fromone to four carbon atoms, R2 and R3 are independently selected from thegroup consisting of hydrogen and methyl, m and n are positive integerswhose sum is from 2 to 20, and with the proviso that one of R2 and R3 ismethyl and one of R2 and R3 is hydrogen; (c) a borate ester of theformula: (R1(Rg)O)3-B, wherein R1 is alkyl of from one to four carbonatoms, Rg is a heteric oxyalkylene chain of the formula: (- (OCH2CH2)r ,(OCH2CHCH3)s -) , wherein the sum of r and s is not more than 20 andwherein the weight percent of the oxyethylene units is not less than 20based on the total weight of all the oxyalkylene units; and (d) a borateester of the formula:
 9. The hydraulic fluid composition of claim 2which contains from 0 to about 8.0 percent by weight of at least onesaid inhibitor for pH and corrosion control and from 0 to about 2.0percent by weight of at least one antioxidant.
 10. The hydraulic fluidcomposition of claim 2 wherein said base fluid or lubricant is at leastone borate ester of type (a).
 11. The hydraulic fluid composition ofclaim 10 wherein said diluent is of type (i).
 12. The hydraulic fluidcomposition of claim 11 which contains from about 0.2 to about 6.0percent by weight, based on the total weight of the hydraulic fluid, ofat least one said inhibitor for pH and corrosion control.
 13. Thehydraulic fluid composition of claim 12 which contains from about 0.001to about 1.0 percent by weight, based on the total weight of thehydraulic fluid, of at least one said antioxidant.
 14. The hydraulicfluid composition of claim 2 wherein said base fluid or lubricantconsists essentially of from about 30 to about 54.4 percent by weight,based on the total weight of the hydraulic fluid composition.
 15. Thehydraulic fluid composition of claim 14 wherein said base fluid orlubricant is at least one borate ester of type (a).
 16. The hydraulicfluid composition of claim 15 wherein said borate ester of type (a) hasan R1 alkyl group of one to two carbon atoms and an Ra alkylene group of2 to
 3. 17. The hydraulic fluid composition of claim 15 wherein saidborate ester of type (a) is selected from the group consisting of(CH3(OCH2CH2)3O)3-B, (C2H5(OCH2CH2)2O)3-B, (C2H5(OCH2CH2)3O)3-B,(C2H5(OCH2CH2)4O)3-B, (C3H7(OCH2CH2)3O)3-B, (C4H9(OCH2CH2)2O)3-B, and(C4H9(OCH2CH2)3O)3-B.
 18. The hydraulic fluid composition of claim 15wherein said diluent is at least one glycol ether of type (i).
 19. Thehydraulic fluid composition of claim 18 wherein said glycol ether oftype (i) has an alkyl R group of one to two carbon atoms, an R''selected from the group consisting of hydrogen and alkyl of one to twocarbon atoms and an alkylene R'''' group of from two to three carbonatoms.
 20. The hydraulic fluid composition of claim 18 wherein saidglycol ether is selected from the group consisting of diethylene glycolmonomethyl ether, diethylene glycol monoethyl ether, diethylene glycolmonobutyl ether, triethylene glycol monomethyl ether, triethylene glycolmonoethyl ether, triethylene glycol monobutyl ether, tetraethyleneglycol monomethyl ether and tetraethylene glycol monobutyl ether. 21.The hydraulic fluid composition of claim 18 which contains from about0.2 to about 6.0 percent by weight, based on the total weight of thehydraulic fluid of at least one inhibitor for pH and corrosion control.22. The hydraulic fluid composition of claim 21 which contains fromabout 0.001 to about 1.0 percent by weight, based on the total weight ofthe hydraulic fluid, of at least one antioxidant.
 23. In the operationof a fluid pressure operating device which uses hydraulic pressuretransmission fluid, the improvement comprising using as said hydraulicpressure transmission fluid a composition consisting essentially of fromabout 20 to about 54.4 percent by weight, based on the total weight ofthe hydraulic fluid composition, of at least one borate ester base fluidor lubricant selected from the group consisting of (a) a borate ester ofthe formula: (R1(O-Ra)y-O)3-B , wherein R1 is alkyl of from one to fourcarbon atoms, Ra is alkylene of from two to four carbon atoms and y isan integer of from 2 to 4; (b) a borate ester of the formula:(R1-(OCH2CHR2)m-(OCH2CHR3)nO)3-B , wherein R1 is alkyl of from one tofour carbon atoms, R2 and R3 are independently selected from the groupconsisting of hydrogen and methyl, m and n are positive integers whosesum is from 2 to 20, and with the proviso that one of R2 and R3 ismethyl and one of R2 and R3 is hydrogen; (c) a borate ester of theformula: (R1(Rg)O)3-B , wherein R1 is alkyl of from one to four carbonatoms, Rg is a heteric oxyalkylene chain of the formula: (- (OCH2CH2)r ,(OCH2CHCH3)s -) wherein the sum of r and s is not more than 20 andwherein the weight percent of the oxyethylene units is not less than 20based on the total weight of all the oxyalkylene units; and (d) a borateester of the formula:
 24. The process of claim 23 wherein there is fromabout 30 to about 54.4 percent by weight, based on the total weight ofthe hydraulic fluid composition, of said base fluid or lubricant. 25.The process of claim 24, wherein said base fluid or lubricant includesat least one borate ester of type (a).